How did you know you were controlling your device by Roku hdmi-cec? And not the Tv's cec commands? Did the volume stop working when you unplugged the hdmi cable from the Roku device? What told you it was cec and not IR in the first place?
I am using a Yamaha A/V surround sound receiver and the ROKU does not support IR for the device. I also had to specifically enable HDMI CEC on my receiver before the volume controls started working when I initially got my ROKU.
What model of Roku is it, and model number of the Roku remote? If it's so old that it doesn't have IR on board, where the volume keys weren't meant to control tv's & audio devices initially but only the headphone jack on the remote. Only later an upgrade allowed it to control devices by cec. I need to know because there is way to switch from IR to cec, but those older remotes and devices it won't work.
My streaming stick is the ROKU Streaming Stick+ 3810X running the 11.5.0 build 4235-50 software version. The remote is a "Voice Remote" - RC399 with a firmware version of rtn.4182. It does have IR on the remote but not for A/V receivers.
Also, just as an FYI, I can change the HDMI input on my receiver and hit "any key" to have it switch back to the correct HDMI for the ROKU too so I don't think I am having an issue with my receiver and the HDMI CEC configuration on the receiver.
See PM.
